A Little Known Way To Sanitize Your Carboys

sanitizing_carboyI’ve heard that Pot Met [potassium metabisulfite] does not need to touch the carboy or bottles to sanitize, but the fumes are what actually does the sanitizing. Can you tell me which is correct?
Name: Bob
State: NY
Hello Bob,
What you have stated above is correct. The SO2 gas that releases from a solution of water and potassium metabisulfite will sanitize the inside of your secondary carboys and primary fermenter buckets. It’s very effective, simple to do, and cost efficient.
Put about 2 or 3 inches of water in the bottom of your carboy, then add 1 teaspoon of potassium metabisulfite. It is also very important that you add 1/2 teaspoon of citric acid along with it. Without the citric acid, the SO2 will not release readily enough to do the sanitizing. If you are doing this in a bucket-style primary fermenter you will want to put the lid loosely on the fermenter to cause the gas to linger longer. Do not seal the fermenter or carboy air-tight. Allow the fumes to vent.
You only need to let the sulfite/water solution fume for about 30 minutes, and the fermenter will be sanitized. No need to rinse anything off. Just dump the solution out of the fermenter then add your wine.Shop Sodium Metabisulfite
To take this method of sanitizing a fermenter even further, you can also put your smaller pieces of wine making equipment in a primary fermenter while sanitizing it. You can put in: hydrometers, siphon hose, rubber stoppers, air-locks. Anything that will fit in fermenter, and all will be sanitized at the same time.
This method works whether you use the potassium metabisulfite, sodium metabisulfite or Campden tablets. All can be added to water with citric acid to make this fuming sanitizing solutions. To read more about these sulfites you may want to take a look at another blog post: “A Simple Guide To Metabisulfites“.
This using sulfite fumes to sanitize can also be applied to wine bottles just as well. Mix up the solution and add an inch or two to each wine bottle. Let sit for 30 minutes; drain then use.shop_wine_bottles
Using a sulfite solution is an easy and effective way to sanitize your carboy and other fermenters and equipment. Hope this information helps you out.
Happy Winemaking,
Ed Kraus
Ed Kraus is a 3rd generation home brewer/winemaker and has been an owner of E. C. Kraus since 1999. He has been helping individuals make better wine and beer for over 25 years.

0 thoughts on “A Little Known Way To Sanitize Your Carboys

  1. Can the typical wine making acid such as Kraus’ "Wine Making Blend" be used in lieu of straight citric acid w/ the Pot Met in this sanitizing solution? Can straight – or concentrated – lemon or lime juice be used? Thanks for this great service!

  2. Can Acid Blend be used in place of citric acid when combining with potassium metabisulfite to sanitize carboys, ect…?

  3. Jeff, yes you can use Acid Blend in place of citric acid. Use the same amount and you will be fine. We do not have any experience with using lemon juice. The biggest problem that can be seen immediately is, how much to use? Lemon juice is not nearly as acidic as Acid Blend or citric acid, so it would be hard to tell. If it was my wine on the line, I would not risk messing around with lemon juice.

  4. Nathan, you will want to use 16 Campden tablets for each gallon of water. Crush the tablets up first so that they will dissolve.

  5. when wine is aging in 5 gallon glass carboys for months & months & gets small additions of sulphites every couple of months when racking as always suggested for better keeping qualities should a fermentation lock be in use or just tightly seal with rubber or plastic stopper until ready to bottle ?????

  6. Mike, it is always better to seal the wine up with a solid rubber stopper. I would also suggest wiring down the rubber stopper with some bailing wire or something similar. It is possible for the rubber stopper to pop out, particularly if the wine warms up a few degrees and expands.

  7. When done with my solution of sulfite I always dump it into one of my empty carboys to keep them sanitary. I rinse them out before using again. Also store in my 1 gal containers as well. Keeps the inside from drying out and they clean up with just a rinse before use again.

  8. Concerning your article on "A little Known Way To Sanitize You Carboys" and the comment:
    Secondly, this method of sanitation can also be applied to wine bottles just as well.
    Mix up the solution and add an inch or two to each wine bottle. Let sit for 30 minutes; drain then use.

    I have a number of barrel fermenters. Can I put the solution, and my bottles, in a barrel fermenter and sanitize them?

  9. Paul, this solution has a very short shelf-life when in the wine bottles. No more than the sulfite cost, I would never risk an entire batch over such little money. Mix up a fresh solution for your barrel fermenters.

  10. I usually make a red wine (merlot) and a white wine (pinot gregio) at the same time. Can I use the same yeast for both

  11. This is not totally true. Your carboy must be free from any residual particles and films from prior use. This is impossible to do with a gas. It must be scrubbed with a long handled brush. Even with a brush it is hard to achieve because one can’t actually get enough pressure on the inside to “scrub” through the small opening at the top.
    The high acids and alcohol of wine can help hinder the growth of spoilage bacteria.
    However beer is a different story. Use something close to caustic for your beer carboys.

  12. I don’t have any citric acid to add to the potassium metabisulfite and water solution for sanitizing my carboy today…Is there a suitable substitute? Ascorbate Acid?? Whatever??

    • George, you can add any of the acids to the sulfite and it will be an effective sanitizer. It is fine to us ascorbic acid.